For example, solar panel production requires a lot of electricity. That electricity is mostly generated from fossil fuels. But if you supplied that electricity with solar panels instead, it would be way cleaner. Which is correct? We should probably present both numbers, if possible.
It starts to sounds complicated, and to be a lot of information to digest for a decision, but another way of looking at it is that correctly assessing and planning for energy needs in the future is so important that ignoring information like that when making an assessment is irresponsible. We need more nytimes.com style widgets that allow you to tweak the values to easily digest data like this, and that clearly reference where the data and assumptions come from.